Literature Review

This guide provides information to understand the purpose of a Literature review, search for information, analysis; synthesis of the literature and writing the review.

Starting your search

There are seven basic steps in the search process:

  1. Identifying the key words and phrases that reflect the key concepts of your research topic.
  2. Formatting these key words and phrases using techniques such as phrase searching and truncation that make the most of them.
  3. Turning these key words and phrases into effective searches using a few easy to master techniques.
  4. Using the filters and limits in databases to optimise your searches.
  5. Reviewing/evaluating your search results.
  6. Making the most of your search results – by using the information in database records and article reference lists to find other resources.
  7. Search again – Searching is not a linear process. And it is not enough to do just one search. You will need separate searches for each aspect of your topic. You will also need to repeat your searches in multiple databases. As you continue to search and read the literature related to your topic, you will find that you need to modify your searches to include the other keywords you come across, or other aspects of the topic you need to investigate.

Step 1 - Identifying your keywords

Start by writing out your research question. You need to filter out the words that are not going to be useful for your search. Search engines will search for exactly what you type into them, including words like "the". You need to make sure you're only using the words that represent your key concepts.

  1. Underline the words that tell you what to do with the information once you've found it, evaluated it and thought about it. They're relevant to the writing you will do later. You don't need them now.
  2. Circle any limits in the question. Some examples of these are: geographical locations, periods in history, demographic groups, specific types of clinical tests, or the date range for the literature you are searching. These will help you to refine your search. Some of these limits will be used as keywords. Some will be filters in a database.
  3. Now look at the words that are left. Highlight the words and phrases that represent the key concepts you are searching for information on.
  4. Draw a table. Write the word or phrase for one concept at the top of each column.
  5. If you know of any alternate ways of expressing a concept, write those underneath that concept. This includes alternate spellings and acronyms. Don't worry if you can't think of any alternate words at this stage. You'll find more as you search. This is just a starting point.
effect ozone layer pollution computer modelling
impact
consequences
repercussions
    computer modeling
computer simulation

Note:If you are studying health and medical sciences, you will also need to think about the MeSH terms for your keywords. The Using Health and Medical Sciences guide has information on how to do this.

Step 2 - Phrase searching, Truncation, Wildcards, Plurals

After you identify the key concepts you need to find information on, you can use these techniques to maximise the potential of each of the words and phrases:

  • Phrase searching: Sometimes an idea is represented by a group of two or more words. In searching this is referred to as a phrase. To search for a phrase, use double quotation marks around the words, e.g. "ozone layer". This tells the database to search for occurrences of this specific group of words in exactly this order.

  • Truncation: When there are various forms of a word, you can cut it back to the root word and add a truncation symbol, e.g. pollut* will search for pollution, pollute, pollutes, polluter, polluters, polluted, polluting, pollutant, pollutants. It's the short version of (pollution OR pollute OR pollutes OR polluter OR polluters OR polluted OR polluting OR pollutant OR pollutants). Truncation symbols vary slightly between databases, so use the 'Help' or 'Search Tips' options to check which one you need.

  • Wildcards: There may be variations in the spelling of words, e.g. British English and American English have different spellings for some words. If you search with only one spelling, you will miss the relevant results with the alternate spelling. A wildcard character is a symbol that can be used to replace a letter within a word, e.g. organi?ation will search for both organisation and organization. Wildcard symbols vary slightly between databases, so use the 'Help' or 'Search Tips' options to check which one you need.

  • Plural terms: Check how the database you are using searches for single/plural versions of keywords - this can have a huge impact on your results, as some databases will automatically search for the plural version of a singular term, but not the reverse (this information is usually included under 'Help' or 'Search Tips').

Step 3 - Combining the words using Boolean operators

Keywords can be formatted and combined into searches using specific words and symbols. You can use these techniques to maximise the effectiveness of your searches and get better quality results.

  • AND – is used to combine words for different concepts, e.g. "ozone layer" AND pollution. It tells the database to find results where all the of the words appear. It narrows your search.

  • OR – is used to add synonyms or similar concepts to the search. It tells the database to find results where one of the words or phrases appears, e.g. effect OR impact OR consequences OR repercussions. It broadens your search.

  • NOT – is used to exclude terms you don't want to find. It narrows your search.

  • brackets () – are used when you are using both AND and OR in a basic search. Because there is only one search box in a basic search, brackets are needed to group the synonyms that are combined using OR. The other words that have been combined with AND go outside the brackets, e.g. (effect OR impact OR consequences OR repercussions) AND "ozone layer" AND pollution. This tells the database to find at least one of the words or phrases from within the brackets as well as all of the words that are outside the brackets. It is a way of doing multiple searches at the same time.

Demonstration: You may find it easier to understand how using AND, OR and NOT work by watching them is use.

Step 4 - Limiters

Most databases provide a range of options which enable you to refine your search results by manipulating specific elements of your search. Each database has it's own options for refining the search, the following are common to most databases:

Basic limits There are basic limits that usually just require you to tick a checkbox, or select/enter dates. These are usually near the top of the menu and include:

  • Publication Date
  • Peer-reviewed content
  • Type of Publication

Article type Some databases allow you to limit your search to a specific type of document, e.g:

  • Academic journal articles
  • Case studies
  • Conference papers
  • Technical papers
  • Reports
  • Review articles

Specific fields All databases organise information about their documents into specific fields. You can use theses fields to build much more accurate searches. If you go to the Advanced Search you'll find a dropdown list of available fields next to each search box. Enter your words into the box and select the field you want to search for them in. Examples of searchable fields include:

  • Author
  • Title – this is the article title
  • Subject
  • Abstract – this is the summary of the article.
  • Title, Abstract and Keywords
  • All except full text – this is all fields of the record but not the full article. It includes the abstract.
  • Publication Name – this is the journal title

Below is a video, produced by Curtin University, that demonstrates searching with keywords and searching with subject terms so you can see the difference in results.

Step 5 - Reviewing and evaluating your results

You need to review your search results both during, and after, your searches. This helps to ensure that your results are relevant and comprehensive.

During your searches:

  • Think about the number of results. New areas of research may only have a few dozen articles published whilst a well-established area will have hundreds (or more).Generally, aim for results lists with no more than 100-150 articles per search - larger numbers will be difficult to work through, and may indicate that your search has not focused closely enough on specific aspects of your topic.

  • Briefly review each article. Don't rely on the article title. Read the abstract to get a clearer picture of what is covered in the article. This will help you short-list the articles that are most likely to be relevant. You will still need to read the full article for everything in your short-list, to determine whether you can use it or not, but you will have a smaller number to read in full.

  • As you work through the articles, you might like to check whether you have a balance between research and review articles, and recent and older research. The preferred balance will vary according to the nature of the topic.

  • For more information on evaluating sources see the Evaluating Books, Journals, Journal Articles and Websites guide.

After your searches:

Consider your results as a whole. If you have some familiarity with the topic, you may be able to identify whether well-known researchers are represented in your results, or research that you were already aware of (if not, why not?). Consider whether the results appear to be a fair representation of what you would have expected to find, or whether there are elements missing.

Step 6 - Making the most of your search results

Databases are designed to be mined for information, so make the most of them and get as much information as you can from your search results:

  • Once you have located a relevant citation, look at the complete record to see if there are other terms listed which might be useful for searching. Depending on the database you are using, these may be called subject headings, descriptors, concepts, codes etc.

  • Check the reference lists of relevant articles for other relevant citations.

  • If you have identified significant researcher/s, try an Author search on their name/s.

  • If you are using the Scopus database, use the cited by links to see how other authors have utilised a particular article. For Web of Science use the Times cited links.

  • If a particular search has yielded good results, consider creating an alert for it. This instructs the database to run the search automatically on a regular basis, and notify you when new articles are published in your area of interest. The Alerting and Current Awareness Services Library Guide provides links to more details.